Socket wrenches

ABSTRACT

A wrench tool, such as a T wrench, including at least one wrench socket which can receive insertion into its recessed interior of a fastener-head of either of two types which differ from each other in shape and/or size and to engage the inserted head with an appropriate amount of torque-imparting contact between portions of the socket&#39;&#39;s interior surfaces and corresponding portions of outside surfaces of the head for it to be able to impart substantially as much torque thereto as it would be able to impart to a fastener head of the other type should that head, instead, be inserted into the socket. The recessed interior of the socket comprises: (1) an entrance-portion which extends into the socket for a distance d from its plane of entrance; and (2) a deeper-lying-portion which extends for a distance d&#39;&#39; from the bottom of the entrance portion to the bottom of the recessed interior of the socket. The entrance-portion can receive insertion of a fastener-head of either of said two types and thereupon contact portions of exterior torque-receiving surfaces thereof with portions of its interior torque-imparting surfaces comprised in a respective one of two different groups thereof, but, depending upon the extent to which said heads differ from each other in shape and/or size, the sums of the areas of the head-contacting and torque-imparting surfaces comprised in the subdivisions included respectively in said two different groups thereof may be substantially unequal. To compensate for this the socket is so formed that any inserted fastener-head of the type which the entrance-portion is able to engage with substantially more of its torqueimparting interior-surface areas than it can a head of the other type is prevented from being inserted into the socket beyond the bottom of the entrance-portion whereas a fastener-head of the other type, after it has been fully inserted into the entrance portion, will be free to move more deeply into the socket and, if this fastener-head is long enough, to be fully inserted into the more-deeply-lying portion for its full depth d&#39;&#39; whereupon it will be engaged by additional torque-imparting interior surfaces of that portion. The ratio of (d plus d&#39;&#39;) to d is such that, due to the additional torque which can be imparted in this manner to a fastener-head of said other type by interior surfaces of the deeper-lying-portion, the socket is able to apply substantially equal amounts of torque to fastener-heads of the two types.

United States Patent [1 1 Erin [451 Apr. 15, 1975 1 SOCKET WRENCHES [76]Inventor: Harold Gustave Erm, 128 Westover Ave., West Caldwell, NJ.07006 [22] Filed: Jan. 2, 1973 [21] Appl. No.2 320,658

[52] U.S. Cl 81/121 R [51] Int. Cl B25b 13/06 [58] Field of Search81/121 R, 121 B, 177 B, 81/177 G, 185, 177 R [56] References CitedUNITED STATES PATENTS 838,109 12/1906 Hanes et a1. 81/121 RX 1,584,2085/1926 Bellows 81/121 R 2,054,978 9/1936 Hoelscher.. 81/121 R X2,502,587 4/1950 Phipps 81/185 2,878,701 3/1959 Weersma 81/121 R XFOREIGN PATENTS OR APPLICATIONS 1,240,971 8/1960 France 81/177 B PrimaryExaminer-A1 Lawrence Smith Assistant ExaminerJames G. Smith [57]ABSTRACT A wrench tool, such as a T wrench, including at least onewrench socket which can receive insertion into its recessed interior ofa fastener-head of either of two types which differ from each other inshape and/or size and to engage the inserted head with an appropriateamount of torque-imparting contact between portions of the socketsinterior surfaces and corresponding portions of outside surfaces of thehead for it to be able to impart substantially as much torque thereto asit would be able to impart to a fastener head of the other type shouldthat head, instead, be inserted into the socket. The recessed interiorof the socket comprises: (1) an entrance-portion which extends into thesocket for a distance d from its plane of entrance; and (2) adeeper-lying-portion which extends for a dis tance d from the bottom ofthe entrance portion to the bottom of the recessed interior of thesocket. The entrance-portion can receive insertion of a fastenerhead ofeither of said two types and thereupon contact portions of exteriortorque-receiving surfaces thereof with portions of its interiortorque-imparting surfaces comprised in a respective one of two differentgroups thereof, but, depending upon the extent to which said headsdiffer from each other in shape and/or size, the sums of the areas ofthe head-contacting and torqueimparting surfaces comprised in thesubdivisions included respectively in said two different groups thereofmay be substantially unequal. To compensate for this the socket is soformed that any inserted fastener-head of the type which theentrance-portion is able to engage with substantially more of itstorqueimparting interior-surface areas than it can a head of the othertype is prevented from being inserted into the socket beyond the bottomof the entrance-portion whereas a fastener-head of the other type, afterit has been fully inserted into the entrance portion, will be free tomove more deeply into the socket and, if this fastener-head is longenough, to be fully inserted into the more-deeply-lying portion for itsfull depth d whereupon it will be engaged by additional torqueimpartinginterior surfaces of that portion. The ratio of (d plus d) to d is suchthat, due to the additional torque which can be imparted in this mannerto a fastener-head of said other type by interior surfaces of thedeeper-lying-portion, the socket is able to apply substantially equalamounts of torque to fastenerheads of the two types.

2 Claims, 11 Drawing Figures PATENTEDAPR 1 51975 3,877,

snmeq g 6Q SOCKET WRENCHES BACKGROUND OF THE INVENTION This inventionrelates generally to socket wrenches. More particularly it relates to awrench of improved effeciency comprising at least one socket which isadapted to securely grip, for imparting rotational torque threto,fastenerheads of more than a single size and/or shape, e.g., forsecurely gripping different nuts (or stud-heads) which may be (I) of asingle size but different shapes such as square or hexagonal; or (2) ofdifferent sizes and a same shape; or (3) of different sizes anddifferent shapes.

While it has not been an uncommon practice to attempt to use a socketwrench which was intended for gripping one particular type and/or sizeof fastenerhead for gripping one or more others, for example, to use asocket having a twelve-notched interior opening and intendedspecifically for gripping hexagonal fastener-heads of a particular size,for tightening or loosening a squareheaded nut or stud of some hopefullysuitablyrelated size, this frequently incurs serious misuse of one orboth of the wrench and the fastenerhead. Unfortunately, for one whoattempts to do this. the respective dimensions measured across oppositecorners of hexagonal and square fastener-heads of a same (or, for thatmatter, of nearly a same) size" are quite different, e.g., that of anone-half-inch hexagonal fastener-head is: l very much smaller than; (2)substantially smaller than; and (3) substantially larger than those ofsquare fastener-heads of one-half-inch; seven-sixteenths-inch; andthree-eights-inch sizes respectively. Because of the existance ofdifferences like these the usual practice among mechanics who seek touse .(or misuse) sockets in this way is for them to rely on trial anderror in order to find a twelve-notched, or..for that matter., asixnotched, socket, which will happen to afford an approximate fit forthe four corners of a square-headed fastener and then to trust to luckthat neither the fastener nor the tool will be damaged by using it inthis unintended way. In any event this practice is always unsatisfactoryto the extent that it occasions wastage of time due to the use of trialand error. Moreover the liklihood of damage is really considerable foran additional reason besides that of a probable poor size fit. This isthat the gripping corners of either a twelve-notched or a sixnotchedsocket for hexagonal fastener-heads include a much wider angle (120degrees) than that of a 90 degree corner which is most suitable forgripping a square-headed fastener. As a consequence and particularly ifthe fit is at all loose it is not at all uncommon to crack open anhexagonal socket when it is used for applying high torque substantialrotational forces to a squareheaded fastener, and/or to blunt orshearoff the corners of the fastener.

Accordingly it is an object of this invention to provide a wrench socketof improved suitability for quickly, safely, and effectively applyingsubstantial amounts of torque to fastener-heads of more than a singleshape and/or size.

It is a further object to provide a unitary tool which includes at leastone of the novel sockets disclosed herein attached to a free end of oneof at least two cross-connected arms, e.g., cross-connected like a T orL wrench handle, whereby it can handle a substantially larger number offastener-heads than the number of its said sockets, and affords meansfor reaching into wells and/or recesses within which fasteners may belocated, such as oil-drainage plugs in the bottoms of the crankcases ofrotary lawn mowers, and for applying substantial torque to any of itssockets without any need of attaching a separate handle orhandle-extension to it.

In general these and other objects may be attained in accordance withthe present invention by departing from the prior and current practiceof configuring and sizing a socket so that as many portions as possible,i.e., as large a percentage as possible, of the total area of itsrecessed interior will be usefully involved in, and therefore willcontribute to, the functions of holding-captive andconstraining-rotationally a fastener-head of a single particularpredetermined type, i.e., a fastener-head of one particular shape andsize, whenever the socket is used in its intended and normal manner toengage a fastener-head. Instead, according to the present invention asocket is so formed: (1) that respective groups of subdivisions thetotal interior torque-imparting surfaces of an entrance-portion of therecessed interior of the socket are shaped and sized for impartingtorque to different ones of a plurality of fastener-heads of differenttypes, i.e., of fastener-heads of different shapes and/or sizes; and (2)that to this end the torqueimparting surfaces comprised in each of saidgroups of subdivisions, are so configured and sized that they will veryprecisely conform to corresponding portions of outside surfaces of apredetermined different one of said plurality of fastener-heads ofdifferent types.

As will be seen, the sums of the torque-imparting areas of thesubdivisions comprised in the abovementioned respective groups thereofmay be substantially unequal whereby the entrance-portion may not becapable of imparting as much torque to heads ofone type as to others. Tocompensate for this the socket may be so formed: (1) that its recessedinterior also comprises a deeper-lying-portion into which only a head ofsaid one type can be inserted in torquereceiving relationship, and, moreparticularly, that it can do so because when such a head is insertedinto the entrance-portion it will be guided by and thereupon pass thruit into the deeper-lying portion; and (2) that the deeper-lying-portionis provided with headcontacting, torque-imparting interior surfaces allof which are shaped and sized to contact exterior torquereceivingsurfaces of only heads of said one type. Because of this the relativedepths of the entrance-and deeper-lying-portions of the socket may beproportioned so that the socket can impart substantially equal amountsof torque to heads of said different types.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates the undesireabilityof using an hexagonal socket for engaging a square-headed fastener;

FIG. 2 is a side, partially-sectioned view of a T wrench which includestwo sockets of the kind disclosed herein;

FIGS. 2a, 2b, and 2c are end views of three sockets included in the Twrench of FIG. 2; and

FIGS. 3a, 3b, 3c, 3d, 3e, and 3f are end views of respective socketsembodying this invention, FIG. 32 being an enlargement of FIG. 2a andFIG. 312 being an enlargement of FIG. 2b.

DESCRIPTION OF EXEMPLARY PREFERRED EMBODIMENTS Referring now to FIG. 1,which illustrates a common prior and current practice, the recessedinterior of a socket is formed with twelve notches 11 which are soformed that any set of six alternate ones thereof (a set comprising halfof the notches) can fit snugly over and hold closely-captive by all ofits six corners an hexagonal fastener-head of just one predeterminedsize, and, more particularly and to this end, the notches are formed sothat each of them includes an angle of 120 degrees. A squarefastener-head 12 of a size which, in the example shown, is 25% smallerthan the hexagonal-head for which the socket 10 is intended, e.g., a sixeighths inch square head assuming that the socket 10 of FIG. 1 is of oneinch size is represented as contained within the socket. Partly becauseof the fact that the fit of the head 12 in the socket 10 will usually bea very loose one (as a consequence of its being randomly arrived at andtherefore largely a matter of almost pure chance), but also and more sobecause of the fact that the square, ninety degree corners of the head12 can not be gripped snugly in the 120 degree notches 11, when torqueis applied, as shown as rotational force at 13, it will cause thecorners of the head 12 to slide against the sloped sides 14 of thenotches causing a large part of that force to be converted intocomponents-which are directed outward radially and which in actualpractice will often prove to be large enough to stretch the recessedinterior of the socket along a diameter thereof and even to break itopen. If the material of the head is softer than that of the socket itscorners may become rounded and/or shorn-off, and, if the socket materialbe quite brittle, both undesireable types of damage may ensue.

Referring now to FIG. 2, there is shown a T wrench comprising alever-arm 21 and a cross-arm 22 and three sockets 23, 24, and attachedrespectively to: the free end of the lever-arm; the left free end of thecross-arm; and the right free end of the cross-arm (as they appear inthe drawing). In the socket 23 (see FIGS. 2a and 3e) and also in thesomewhat similar socket 23 (see FIG. 3e), the periphery of the recessedinterior of the socket, i.e., the distance around its recessed interiornear to the entrance thereof, comprises two groups of subdivisions: afirst group of subdivisions 31 which provide the socket with thecapability of holding snugly captive within the socket a firstparticular type of fastener-head, namely a square head represented indotted outline at 34, of a predetermined size; and, (b) a second groupof subdivisions 32 which provide the socket with the same capabilitywith respect to a second particular type, namely an hexagonal headrepresented in dotted outline at 35, of slightly larger size. It is tobe understood that for the purposes of this specification the intendedmeaning of the word size is: (l as applied to a fastener head, thedistance between pairs of opposite, parallel, and similiarly spacedexternal flat sides of the head, such as the distance between the sides36 of head 34 or the distance between the sides 37 of the head 35; and(2) as applied to a socket, the distance between respestive pairs ofinternal flat surfaces thereof between which pairs ofthe above mentionedexternal flat sides will be held captve in the intended use of thesocket.

The particular size relationship between the heads 34 and 35 which hasbeen chosen as an illustrative example herein, i.e., solely by way ofexample, is that the size of the square one is 12 and /2 percent smallerthan that of the hexagonal one, e.g., that the former may be 7/l6ths ofan inch in an embodiment of this sort wherein the latter is one-halfinch.

It is noted that the sum of the lengths of the subdivisions 32comprising one group thereof which are allotted to contacting externalsurfaces of the hexagonal head 35 for imparting torque thereto comprisesabout of the total peripheral distance as measured around the recessedinterior of the socket 23 in a plane parallel to its plane of entranceand that the sum of the lengths of those 31, comprising a second groupthereof which are allotted to so contacting exterior surfaces of thesquare head 34 comprises a substantially smaller percentage thereof,namely 40% thereof, which in this embodiment is the remainder of thattotal distance, inasmuch as in this embodiment the subdivisions aremutually exclusive. Tho in the case of the particular embodiment 23 thegroups comprising the subdivisions 31 and 32 respectfully do happen tobe mutuallyexclusive, as shown in FIG. 3d they do not necessarily haveto be, and, in fact, whenever possible it will be advantageous if theyare not, since this will usually increase the over-all torque-impartingcapability of the socket.

As shown in various forms in each of FIGS. 2, 3a, 3b, 3c, 3d, 3e, and3f, it is also possible to allott respective portions of the potentiallyusable areas of interior surfaces of sockets as measured in the depthdirection (i.e., as measured inwards from the entrance planes of socketstoward their bottoms) to afford the respective portions with thecapability, in the manner explained above, of imparting torque todifferent predetermined types of fastener-heads. For example in the caseof the socket 23, two portions of its recessed interior, anentrance-portion a (of a depth d as measured into the socket towards itsbottom from its plane of entrance) and a deeper-lying-portion d (of adepth d' as measured from the bottom of the entrance-portion to thebottom of the socket), are respectively allotted as follows: l theportion d is allotted to holding captive for imparting torque theretoeither an hexagonal head of a certain size or a square head of a 12.5%smaller size, this portion of the socket being capable of receiving onlya portion of the end of such an hexagonal head which, as measured alongits length-dimension (measured in the direction of its rotational axisfor tightening or loosening), is no longer than the distance d (or ofreceiving all of such an hexagonal head if its length is no greater than(I); and (2) the deeper-lying-portion d is allotted to holding captivethe end portion of a square fastener-head which is long enough to beinsertable into the socket more deeply than the distance d. It will beapparent from the foregoing that by proper choice of the ratio betweenthe dimensions d and d it will be possible to compensate for thedifference (60% vs 40%) between the respective amounts of peripheralengagement between the entrance-portion of the recessed interior of thesocket and the two different fastener-heads which that portion isadapted to grip whereby to provide the socket with substantially equaltorque-imparting capability with respect to both.

Referring now to FIG. 3d, the socket 43 shown therein, like the socket23 of FIG. 30, comprises two groups of subdivisions of the peripheraldistance around its recessed interior (groups 41 and 42) which areallotted respectively to providing it with the capability of contactingto impart torque to two different types of fastener-heads, namelyhexagonal and square heads of a same size. It is noted that in thiscase, as contrasted to that of the socket 23, not all of the peripheralsubdivisions are mutually exclusive. Thus in this socket: (l) a centralperipheral subdivision 42 of each of the two flat inside surfaces 45 ofthe recessed interior of the socket 43 is adapted to engage all of oneof the six flat surfaces comprising the exterior of an hexagaonal head;and (2) all of each of these same surfaces 45 is adapted to engage allof one of the four flat exterior surfaces of a square head. The abovereferances to subdivisions of (or all of) an interior wall" or of anexternal surface" are intended to mean of the peripheral distance acrosssaid wall as measured in a direction parallel to the plane of entranceof the socket and of the corresponding peripheral distance across saidexterior surface measured in a direction which is parallel to itsintended plane of rotation. Insofar as the two fasteners which thesocket 43 is intended to engage are hexagonal and square it resemblesthe socket 23. However it does not resemble it in that the presentfasteners are of the same size. In the use of this socket (43) about 51%of the total peripheral distance around an hexagonal head can becontacted in torque-imparting relationship by a group of surfaces thesum of whose widths as measured in a plane of rotation of the socketcomprises about 33% of the total peripheral distance measured around therecessed interior of the entrance-portion of the socket. While this isvery good, e.g., it compares very favorably with what can be provided bythe use of a conventional twelve-notched socket, this same socket (43)affords very much better gripping capability with respect to how much ofthe peripheral distance around a square head it can contact. namely,about 86%.

If desired it is possible to compensate for this disparity by allottingmore of the depth of the socket 43 to holding an hexagonal than a squarehead. Thus the depth down to which a square head may go when it isinserted into this socket is limited by four shoulders (or ledges) 44beyond which there is located a and deeperlying portion of the recessedinterior of the socket 100% of the periphery of which is allotted togripping the top portion of an hexagonal head which can reach into thesocket deeply enough to pass the plane of the shoulders 44.

The socket 24 shown in FIG. 3b is adapted to grip either of twofastener-heads both of which are hexagonal but one of which is slightly,about 8%, smaller than the other, and also, optionally as explainedbelow, one which is square. Examples of heads of such relative sizes arethose of the 13/16 and three-fourths inch spark plugs employed in largenumbers on small (yard power-tool) gasoline motors. In this embodimentthe allottment of respective subdivisions of interior surfaces of thesocket 24 to the function of engaging different types of fastener-headsis made only in the direction of its depth-dimension (d" and d' FIG. 2).If these subdivisions, i.e., entrance-portion d" anddeeper-lying-portion d, are made to be substantially equal to each otherand if their sum be made equal to the average of the depth-dimensions ofan adequate-numerical sampling of (N) heads of the two types, e.g., ofthirteen-sixteenths and three-fourths inch hexagonal heads, which thesocket is intended to engage, then in most cases it will be able toengage about 50% of the exterior torque-imparting surfaces of anyparticular one of these heads. In general this should be quite adequate,since, for example, it greatly exceeds the percentage of such surfacesof such hexagonal heads which can be gripped by either an open-endwrench (whether of fixed size or adjustible, i.e., or a monkey" wrench)or a twelve-notched box wrench. Moreover in the particular case of sparkplugs which do not require the use of extreme amounts of torque ineither rotational direction, it should be even more adequate. Because ofthis it may be quite feasable, for such a specific embodiment, i.e.,where the socket is intended for sparkplugs and therefore thetorque-imparting requirements are moderate, to further reduce therespective percentages of the total area of interior surfaces of thesocket 24 which are allotted to the gripping of the two types of headsmentioned above by suitably notching both the entranceand deeper-lyingportions of the recessed interior of the socket to form additionalperipheral subdivisions 46 whereby to enabling the socket to acceptinsertion of a third type of fastener-head, in the example suggested bythe dotted lines 47 in FIG. 3a, a five-eighths inch square head and toengage that head in the subdivisions 46. Moreover, since a socket ofthis type is unusually deep because it is intended to accept insertionof the porcelain tips of spark plugs, the most-deeply-lying-portion ofthe recessed interior of the socket may be shaped and sized to engagetop portions of exterior surfaces of a head 47 should it be long enoughto extend into the socket beyond both the entrance-portion d and thedeeper-lying-portion d" of its recessed interior.

Tho the socket 50 of FIG. 3f embodies a different specific way ofpracticing the present invention than the socket 24 of FIG. 3b, they areboth adapted to engage the same two different types of fastener-heads(both hexagonal but one 8% smaller than the other). In the socket 50certain peripheral subdivisions 48 of its entrance-portion are allottedexclusively to the function of engaging corresponding portions ofexterior surfaces of hexagonal heads of the smaller of the two sizes.i.e., they do not engage any portion of the periphery of exteriorsurfaces of heads of the larger of the two sizes. In this embodiment theshoulders (or ledges) 49 establish a stopping-plane or depth-limitbeyond which a head of the'larger of the two sizes will be unable tomove more deeply into the socket whereas a head of the smaller size willbe free to move into the socket for I all of its length dimension.

It is noted that this socket may be misused in somewhat the same manneras was explained above with reference to FIG. 1 if one should becareless in attempting to employ it to engage a head of the smaller ofthe two sizes and if he should as a result insert it without the cornersof the head being fitted into the subdivisions 48. As a result of doingthis: (1) the fit will be loose; (2) the insertion of the head will beprematurely stopped at the shoulders 49; and (3) due to (1) and (2), itmay be possible to impose undesirable stresses on the socket indirections which tend to spread or break it. However it should not bedifficult to avoid such possible misuse by watching for loosness of fitand limited depth of insertion. Moreover, even if one should insert asmall head incorrectly, the undesireable radial pressures which will beexerted when torque is applied will occur at six points which aresymetrically distributed around the perimeter of the interior of thesocket rather than just four points as shown in FIG. 1 and therefore theresults may be less harmful. This will be especially true when thesocket 50 is used for engaging spark plugs because of the relatively lowtorques required.

The socket 52 of FIG. 3c combines features of the socket 23 (of FIGS. 2,2a, and 3e) and the socket 43 (of FIG. 3d) in such a way that this onesocket is adapted to engage three different types of fastenerheads; (I)an hexagonal head of a predetermined size; (2) a square head of anapproximately 12.5% smaller size; and a square head of the same size asthe hexagonal head. As shown in FIG. 3d and explained above, anhexagonal head can be inserted more deeply into the socket 43 than anequally sized square head which is stopped by the shoulders 44 at thebottom of the entrance-portion of its recessed interior, and, as shownin FIG. 3e. a square head can be more deeply inserted into the socket 23than a larger sized hexagonal head which is stopped by the shoulders 33and 39 at the bottom of the entrance-portion of its recessed interior.Likewise, in the case of the socket 52 the larger of the two squareheads which this socket is intended to engage and which is of the samesize as an hexagonal head which it can also engage will be stopped byfour shoulders 54 at the bottom of the entrance-portion of its recessedinterior beyond which, however. such an hexagonal head will be able tomove and to enter more deeply into the socket. It is noted that theshoulders 54 thus serve in the socket 52 a purpose which is similar tothat served by the shoulders 44 of FIG. 3d. And, likewise, an hexagonalhead which this socket is intended to engage will be stopped at thebottom of a more-deeply-lyingportion of its recessed interior byshoulders 55 and 56 (which correspond to the shoulders 33 and 39 of FIG.3e). On the other hand, a square-headed fastener of the smaller of thetwo sizes will be free to move past the four shoulders 54 and all of theshoulders 55 and 56 and thus to enter an even-more-deeply-lying-portionof said recessed interior which is provided in this socket, i.e.. willbe free to be inserted into the socket more deeply than either a squarehead of the larger size or an hexagonal head of the same size. This isdesireable since the peripheral subdivisions 31 which are shaped andsized to contact the smaller square head can not engage it at all withinsaid entrance-portion and, tho they do engage it within saiddeeper-lying-portion, the sum of their areas comprises only about 40% ofthe total area of all of the head-contacting surfaces therewithin. Tocompensate for this by an expediant already explained above the recessedinterior of the socket 52 is formed so that the smaller square head isthe most deeply insertable one of the three heads which this socket canengage.

The socket 60 shown in FIG. 3a is adapted to grip either of two squarefastener heads one of which is about 12.5% smaller than the other, e.g.,one of which is seven-sixteenths of an inch in size (a common size forsquare oil-drainage plugs of small gasoline motors used for yard powertools) whereas the larger of the two is of one-half inch size. In thissocket mutually-exclusive peripheral subdivisions 61 and 62 are allottedto gripping respective heads of the smaller and larger sizes in theentrance-portion of the socket lying between its plane of entrance and aplane containing four shoulders 63 whereby about 43% of thetorque-receiving exterior surfaces of a head of the smaller of the twosizes will be engaged by interior surfaces an entrance-portion of thesocket (down to the shoulders 63) versus almost 70% of thetorque-receiving exterior surfaces of a head of the larger size. Tocompensate for this, in a manner already explained above with referenceto other embodiments, a deeper-lying-portion is provided for the socket60 and four shoulders 63 are provided to limit the depth into the socketto which heads of the larger of the two sizes can enter. In this way:(1) less of the depthdimension of the socket 60 is allotted to grippingheads of the larger of the two sizes: and (2) of the peripheral distancearound the inside of said deeperlying-portion, i.e., of the portionbelow the plane of the shoulders 63 is allotted to engaging heads of thesmaller of the two sizes.

Since all of the torque-imparting gripping surfaces of a wrench-socketare comprised in the side walls of its recessed interior, most of theimprovements disclosed herein with respect to wrench-sockets per se canbe embodied in box wrenches with substantially equal beneficial effects.Accordingly it is to be understood that the term wrench-socket as usedherein and in the appended claims is intended to include sockets thatare open at both ends and therefore have lever arms attached to theirsides rather than to end closures, i.e., to include box wrenches.

It is also to be understood that any statements which may be made aboveto the effect that certain wrenchsockets and fastener-heads are of thesame size are not intended to mean that they are exactly of the samesize, since, of course, such a fastener-head must necessarily beslightly smaller than such a wrench-socket in order to enable it to beinserted thereinto without the use of undue force.

I claim:

1. A wrench-socket which is adapted to receive insertion into itsrecessed interior of a fastener-head of either of two different types,such as of different shapes and/or sizes, and to thereupon engage theinserted head with substantial torque-imparting contact between portionsof interior surfaces of the socket and corresponding portions of outsidesurfaces of said head CHARAC- TERIZED IN:

that said recessed interior of the socket comprises (1) anentrance-portion which extends over a distance d between the plane ofentrance of the socket and a bottom-plane which is parallel thereto andcontains a plurality of shoulders for preventing fastenerheads of one ofsaid two types from being more deeply inserted into the socket than saidbottom-plane and (2) a deeper-lying-portion which extends over adistance a" between said bottomplane and the bottom of the recessedinterior of the socket; that said entrance-portion is adapted to receiveinsertion of a fastener-head of either of said two types as deeply as tosaid bottom-plane and to thereupon engage that head with a respectiveone of two different predetermined amounts of torqueimparting contactbetween portions of its interior surfaces and corresponding portions ofoutside surfaces of the inserted head and that, to that end, saidentrance-portion comprises two different groups of peripheralsubdivisions of its torque-imparting interior surfaces which arerespectively adapted to closely-contact and thereby to engage intorque-imparting-relationship corresponding groups of torque-receivingperipheral subdivisions of exterior surfaces of fastener-heads of saidtwo different types; that said deeper-lying-portion comprises interiorsurfaces which are adapted to closely-contact and thereby to engage intorque-imparting-relationship exterior surfaces of inserted heads ofonly the other of sad two types; that some of said Y group ofsubdivisions of interior surfaces of said entrance-portion which areadapted to contact exterior surfaces of fastener-heads of said othertype are so alligned with predetermined portions of said interiorsurfaces of said deeper-lying-portion that a fastener-head of said othertype upon being inserted into said entrance-portion is guided therethrupast said shoulders and into the deeper-lyingportion whereby interiorsurfaces of both portions (1) and (2) of said recessed interior of thesocket will engage that head in torque-impartingrelationship; that thesum of the areas of all torqueimparting surfaces comprised in the groupof peripheral subdivisions of the entrance-portion which are adapted toengage a head of said other type comprises a substantially smallerpercentage of the sum of all torque-imparting surfaces comprised in saidentrance-portion than the percentage thereof comprised in the sum of theareas of all of said surfaces of said other group of peripheralsubdivisions of the entrance-portion; and that the ratio of (d plus 1)to d is large enough, in proportion to the relative smallness of saidsubstantially smaller percentage for said deeper-lying-portion tocontribute enough additional torque-imparting contact to an insertedhead of said other type to enable the socket to impart substantiallyequal amounts of torque to fastener-heads of said two types.

2. A wrench-tool according to claim 1 including a lever-arm and across-arm attached thereto, each of said arms having at least onefree-end, wherein a wrench-socket is affixed to at least one free-end ofone of said arms.

1. A wrench-socket which is adapted to receive insertion into itsrecessed interior of a fastener-head of either of two different types,such as of different shapes and/or sizes, and to thereupon engage theinserted head with substantial torqueimparting contact between portionsof interior surfaces of the socket and corresponding portions of outsidesurfaces of said head CHARACTERIZED IN: that said recessed interior ofthe socket comprises (1) an entrance-portion which extends over adistance d between the plane of entrance of the socket and abottom-plane which is parallel thereto and contains a plurality ofshoulders for preventing fastenerheads of one of said two types frombeing more deeply inserted into the socket than said bottom-plane and(2) a deeper-lying-portion which extends over a distance d'' betweensaid bottom-plane and the bottom of the recessed interior of the socket;that said entrance-portion is adapted to receive insertion of afastener-head of either of said two types as deeply as to saidbottom-plane and to thereupon engage that head with a respective one oftwo different predetermined amounts of torque-imparting contact betweenportions of its interior surfaces and corresponding portions of outsidesurfaces of the inserted head and that, to that end, saidentrance-portion comprises two different groups of peripheralsubdivisions of its torque-imparting interior surfaces which arerespectively adapted to closely-contact and thereby to engage intorque-imparting-relationship corresponding groups of torque-receivingperipheral subdivisions of exterior surfaces of fastener-heads of saidtwo different types; that said deeper-lying-portion comprises interiorsurfaces which are adapted to closely-contact and thereby to engage intorqueimparting-relationship exterior surfaces of inserted heads of onlythe other of sad two types; that some of said group of subdivisions ofinterior surfaces of said entrance-portion which are adapted to contactexterior surfaces of fastenerheads of said other type are so allignedwith predetermined portions of said interior surfaces of saiddeeper-lyiNg-portion that a fastener-head of said other type upon beinginserted into said entrance-portion is guided therethru past saidshoulders and into the deeper-lying-portion whereby interior surfaces ofboth portions (1) and (2) of said recessed interior of the socket willengage that head in torque-impartingrelationship; that the sum of theareas of all torque-imparting surfaces comprised in the group ofperipheral subdivisions of the entrance-portion which are adapted toengage a head of said other type comprises a substantially smallerpercentage of the sum of all torque-imparting surfaces comprised in saidentrance-portion than the percentage thereof comprised in the sum of theareas of all of said surfaces of said other group of peripheralsubdivisions of the entrance-portion; and that the ratio of (d plus d'')to d is large enough, in proportion to the relative smallness of saidsubstantially smaller percentage for said deeper-lying-portion tocontribute enough additional torque-imparting contact to an insertedhead of said other type to enable the socket to impart substantiallyequal amounts of torque to fastener-heads of said two types.
 2. Awrench-tool according to claim 1 including a lever-arm and a cross-armattached thereto, each of said arms having at least one free-end,wherein a wrench-socket is affixed to at least one free-end of one ofsaid arms.